etc/xbps.conf: improve PackagesOnHold description.
etc/xbps.conf: improve PackagesOnHold description.

stpx/xbps,datenwolf/xbps,ebfe/xbps,stpx/xbps,ebfe/xbps,ebfe/xbps,datenwolf/xbps,datenwolf/xbps,stpx/xbps